Apparatus, methods and systems for handling and processing waste material

ABSTRACT

Apparatus, methods and systems for processing waste are provided. For example, a system for processing waste, wherein the waste comprises hard particulates embedded therein, can be provided. The system can comprise a waste disrupter, wherein the waste disrupter disrupts the waste and releases at least one of the embedded hard particulates from the disrupted waste; a segregator, wherein the segregator segregates at least one of the released hard particulates from the waste; and a dilution unit, wherein the dilution unit dilutes the waste. In some embodiments, the system can include a waste loader that provides waste continuously to the waste disrupter, which is configured to disrupt at least a portion of the continuously provided waste.

This application is a continuation application of U.S. Ser. No.12/004,686, filed on Dec. 21, 2007, now U.S. Pat. No. 7,771,598, theentire content of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to apparatus, methods and systems forhandling and processing waste material.

Organic waste material, such as municipal wastewater or livestockmanure, can present problems when generated on a large scale. Forexample, organic waste material can pose both a health risk and anuisance. Decomposing organic waste can also release greenhouse gases,such as methane and carbon dioxide. Organic waste material can also be apotential source of air and water contamination. Thus, strategies fordealing with organic waste in such quantities are needed.

One possible solution for the problem of organic waste material isconverting or processing the waste into less environmentally noxious orhazardous forms. Such processes may result in useful products derivedfrom the waste, either by converting the waste to such products orextracting products therefrom. Furthermore, many such processes involvesubjecting the waste to controlled processes, thereby allowing controland capture of undesirable by-products, such as greenhouse gases, andisolation of the waste from the environment.

However, compared to other feedstocks, organic waste can be a difficultmaterial to handle and work with during such processes. Typically, wastecan be highly heterogeneous in its composition. For example, livestockmanure can include significant quantities of indigestible non-cellulosicplant matter (e.g. straw, wood) and hard particulates (e.g. sand, rocksand metal), all of which can be agglomerated, with the manure. Theseextraneous components can cause difficulties in handling, or interferewith mechanical, chemical, and biological processes. Organic waste canalso have very high solid content, thereby making it more difficult tohandle and convey compared to more liquefied materials.

Although current methods attempt to address the aforementioned and otherproblems of handling and processing organic waste, these methods havedeficiencies. For example, such quantities of organic waste are usuallysubjected to batch processing, due to the limited capacity of waste thatcan be handled at a given time. However, batch processing can result inlower efficiency, productivity, or both, due to the need for periodicdowntime that results from recharging the batch process with newfeedstock, and removal of processed material.

In view of the foregoing, it would be desirable to have apparatus,methods, and systems for processing waste in a more efficient manner.

It would also be desirable to have apparatus, methods, and systems forprocessing organic waste material to improve handling of said wastematerial.

It would also be desirable to have apparatus, methods, and systems forremoving undesirable contaminants from organic waste material prior toprocessing.

SUMMARY OF THE DISCLOSURE

Apparatus, methods, and systems for handling and processing organicwaste material are provided. The present invention includes apparatus,methods, and systems for processing waste, in which at least a portionof the waste is disrupted to release embedded hard particulates, and thereleased hard particulates are segregated therefrom. The processed wastecan then be diluted to decrease the solid content. Also provided areapparatus, methods, and systems that break up bulky structures containedin the waste, such as lignin, prior to dilution.

For example, a system, method, or apparatus for processing waste,wherein the waste contains hard particulates embedded therein, can beprovided. The system, method, or apparatus can include or use a wastedisrupter, wherein the waste disrupter disrupts at least a portion ofthe waste and thereby releases at least one of the embedded hardparticulates from the disrupted waste; a segregator, wherein thesegregator segregates at least one of the released hard particulatesfrom the waste; and a dilution unit, wherein the dilution unit dilutesthe waste with a liquid diluent.

In some embodiments, the system, method, or apparatus can include or usea waste loader that provides waste continuously to the waste disrupter,which is configured to disrupt at least a portion of the continuouslyprovided waste.

In some embodiments, the segregator is configured to segregate at leastone of the released hard particulates based upon a predetermined minimumsize of the released hard particulates. For example, the segregating canbe performed by size exclusion between the disrupted waste and the hardparticulates. For example, a suitably-sized sieve can be used to retainreleased hard particulates of a given size, while allowing smallerdisrupted waste to pass therethrough.

In other embodiments, segregation by size exclusion can occur bysubjecting waste with embedded hard particulates to a size-limitedaperture or entrance, such that only the smaller-sized waste are able topass through. Larger, released hard particulates are not able to passthrough, and thus can be deflected or diverted from the waste to anotherlocation, thereby segregating the particulates from the waste. In someembodiments, waste can be impelled or otherwise urged towards to thesize exclusion structure so that the waste is also disrupted. In thismanner, disruption and segregation can occur using the same componentstructure.

In some embodiments, the waste disrupter can disrupt the waste byimpacting the waste with another object. In certain embodiments, theorganic waste further comprises metal contaminants, and the system,method, or apparatus can remove at least one of the metal contaminantsfrom the waste. In certain embodiments, at least one of the metalcontaminants can be magnetically removed.

In some preferred embodiments, the waste disrupter includes a disrupterbar, wherein the disrupter bar is positioned above an open augerconveying the waste. Waste being conveyed by the auger can be disruptedupon impact with the disrupter bar, thereby releasing at least one ofthe embedded hard particulates. In some preferred embodiments, thedisrupter entails depositing the waste on a mechanical rotary screeneror like apparatus, thereby releasing at least one of the embedded hardparticulates. The rotary screener can also be configured to segregatedisrupted waste from larger hard particulates, in which the rotaryscreener is sized to permit the smaller-sized waste to pass through, andlarger particulates are conveyed off of the rotary screener.

In other embodiments, the dilution unit may convey the waste afterdilution to an anaerobic bio-digester. In certain embodiments, theliquid diluent can be liquified biodigestate, such as that produced byan anaerobic bio-digester. In some embodiments, the dilution step caninvolve diluting the waste until the solid content of the waste is about12-130%. The waste may in some embodiments also be heated. The waste mayin some embodiments be mixed. Heating the waste may in some embodimentsbe performed by diluting the waste with a liquid diluent having a highertemperature than the waste. In some embodiments, the diluting waste stepcan further comprise paddle mixing the diluted waste.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other advantages of the present invention will become moreapparent upon consideration of the following detailed description, takenin conjunction with the accompanying drawings, in which like referencecharacters refer to like parts throughout, and in which:

FIG. 1 is a flow chart illustrating an exemplary process for processingwaste in accordance with an embodiment of the present invention;

FIG. 2 is a flow chart illustrating an exemplary process for processingwaste in accordance with an embodiment of the present invention;

FIG. 3 illustrates a simplified block diagram illustrating an exemplarysystem for processing waste in accordance with an embodiment of thepresent invention;

FIG. 4 illustrates a simplified block diagram of an exemplary system forprocessing waste in accordance with an embodiment of the presentinvention; and

FIGS. 5A-5B illustrate a side view and a top view, respectively, of anexemplary system for processing waste in accordance with an embodimentof the present invention.

DETAILED DESCRIPTION OF THE DISCLOSURE

Apparatus, methods and systems for processing waste are provided anddescribed with reference to FIGS. 1-5.

Waste, as referred to herein, may be any suitable material that includesorganic and organically-derived matter. For example, waste can includeby-products from industries such as agriculture, food processing, animaland plant processing, and livestock. The waste produced by these andother industries include, but are not limited to: livestock manure,animal carcasses and offal, plant material, wastewater, sewage, foodprocessing waste, and any combination thereof. Waste can also includehuman-derived waste, such as sewage and wastewater, discarded food,plant or animal matter, and the like. Thus, waste used in the presentinvention can be, and typically is, a mixture of normally-discardedorganic matter.

The waste may be provided from any suitable source, including thosedescribed hereinabove. In certain embodiments, the waste source isproximate to the processing location. For example, the present inventionmay process waste generated by a nearby feedlot or wastewater treatmentplant. Such proximity may allow efficient and rapid processing of thewaste. This proximity may also advantageously reduce the amount of timethe waste is idle prior to processing, thereby reducing its potential toact as an environmental nuisance or hazard. In certain embodiments,waste to be processed may be provided from a location or source moredistant from the processing location. The latter positioning may besuitable in cases where the processing location is positioned in acentral location to process waste from multiple sources that aresituated in the local neighborhood or region.

Waste that is processed in accordance with the present invention may bea complex, heterogeneous mixture that can be difficult to handle. Forexample, livestock manure can be collected in large quantities fromfeedlots or other large populations of animals. Such manure, being ananimal waste product, is already a complex mixture of substances.Moreover, manure may also acquire additional contaminants prior to andduring its collection. These contaminant can include, for example,bedding straw, rocks and dirt from the ground, garbage, and otherdebris. Other non-manure contaminants are possible. Furthermore, othertypes of organic waste, including those described herein, each havetheir own risks of collecting heterogeneous contaminating material, oralready include such material due to their origin or any preliminaryprocessing.

These contaminants can be either organic or inorganic in nature.However, such contaminants, if present in the waste in significantquantities, can present several difficulties in view of any furtherprocessing of the waste. For example, certain contaminants, such asrocks and metal, may be incompatible with further processing intendedfor the waste. For example, metal and rocks, unlike organic waste, willnot undergo biological digestion or decomposition, and thus will end upas inert remnants of such processes. In addition, these contaminants,such as rocks and metals which are generally more resistant to physicalforces, may present physical hazards or impediments to subsequentprocesses, or pose a potential to damage equipment used in such furtherprocessing. In addition, rock and metal contaminants are also generallyinsoluble, and thus will impede handling of the waste in liquid form.Therefore, the present invention may provide a solution to reduce, ifnot minimize, the problems caused by such contaminants. Contaminants ofthis type are referred to herein as “hard particulates.”

However, removing such hard particulates from the waste can bedifficult. For one, hard particulates can be embedded into the organicwaste. As a result, merely handling the waste does not necessarilydislodge the particulates sufficiently to allow their removal. Further,organic waste typically has a water content that results in adhesion tothe embedded hard particulates, thereby making their removal moredifficult.

A possible solution to the problem of embedded hard particulates is todilute the organic waste by increasing its water content, whereby thesolid content of the waste is reduced. By diluting the waste to asufficient degree, the embedded hard particulates may be released fromthe waste solids and allowed to settle out. Furthermore, dilution canfacilitate, and may even be required for, subsequent processing of thewaste.

The present invention can address these and other concerns, asillustrated in FIG. 1. This figure shows a flow chart illustrating anexemplary process for processing waste in accordance with the presentinvention.

The present invention includes releasing embedded hard particulates fromwaste by disrupting the waste. In preferred embodiments, this disruptionoccurs prior to substantial dilution of the waste. Thus, for example,the waste may remain in a low-moisture/high-solid form. By disruptingthe waste in this manner, the present invention can improve on dilutionby reducing the need for pre-processing prior to disruption. Otherimprovements can include: preventing the increase of the total volume ofthe waste to an impractical amount (which can increase the costs andburden of conveying the diluted waste), reducing the potential need foradditional processes to retrieve and remove the released particulates,such as by settling (which can be time-consuming), and allowingcontinuous processing to be done, instead of relying solely upon batchprocessing. Continuous processing can reduce idle time, where waste isnot processed, and can thereby avoid further decomposition of theorganic material within the waste, which can lead to reduced yield ofuseful products recovered from the waste.

In some embodiments, pre-processing of the waste may be performed, suchas the addition of supplements to the waste. Such supplements can beuseful in processes that are subsequent to the disruption andsegregation processes. Supplements, can include, for example, glyceroland liquid biodigestate from an anaerobic bio-digester.

Furthermore, the present invention can be advantageous because it canenable continuous processing of waste. Continuous processing can reduceor eliminate down time and increase throughput. Also, such increasedefficiency may also reduce decomposition of the organic prior tobiodigestion.

At step 104 of process 100, at least a portion of the waste isdisrupted, thereby releasing at least one of the embedded hardparticulates from the disrupted waste. Disruption of the waste in thiscontext means mixing, breaking up, fracturing, fragmenting, crushing,impacting, tumbling, flattening, or any other like processes. By theseprocesses, embedded hard particulates are increasingly released, andseparated from the bulk of the waste until released, and the smaller,disrupted waste is less capable of re-embedding or retaining the hardparticulates.

Waste disruption at step 104 can be performed by any suitable apparatus,device, or process. For example, in certain embodiments, devices thatphysically interact with the waste are used. Such devices can include,for example, devices that implement actions such as mixing, breaking-up,crushing, fracturing, impacting, fragmenting, tumbling, flattening, andthe like. These actions may involve direct physical intervention in thewaste (e.g. mixing), or manipulating the waste in a manner that resultsin its disruption (e.g. tumbling). Other suitable devices may implementmore than one of these actions, either simultaneously or sequentially. Asuitable device for performing step 104 may also disrupt the waste in aprocessive manner, in which the initial waste provided is disrupted to agiven degree, and then, as it proceeds through the device, undergoesincreasing degrees of disruption. In this manner, waste may be processedin a more continuous fashion, and the extent of desired waste disruptioncan result from the configuration of the device used.

Other embodiments of the waste-disrupting apparatus can include devicesgenerally used to fragment large material into smaller material, such asan impact crusher, a gyratory crusher, a jaw crusher; or a cone crusher,as are known in the art.

As described above, waste may contain other materials which, althoughthey may be different than the hard particulates, may still disruptsubsequent processes performed on the waste. For example, livestockmanure may contain a significant amount of bedding straw. Straw, likewood, is composed of a non-cellulosic material (lignin) that is moreresistant to digestion or decomposition. Furthermore, due to itsrelatively large size, straw is conducive to forming larger mats andplugs that can interfere with subsequent processes. Breaking up thestraw into smaller fragments may reduce or limit this problem.

Accordingly, a further advantage of the present invention is that thedisruption step may also break up other matter in the waste, such asstraw and other amenable materials. The break-up or disruption of suchstructures may reduce or preclude their interference with later wasteprocessing steps, and may obviate the need for additional processes tospecifically perform this break-up.

It should be noted that at any step of process 100, co-substrates and/orsupplements can be added to the waste. These co-substrates and/orsupplements can comprise organic material, and other supplementalcompounds that can facilitate either the handling of the waste ordownstream processing of the waste. Addition of co-substrates and/orsupplements prior to or concurrent with disruption step 104 may bedesirable in some embodiments, as the disruption step may also act tomix the co-substrates and/or supplements with the waste.

At step 106, hard particulates released from the disrupted waste at step104 are segregated from the waste. In step 104, any suitable device thatcan distinguish and separate the released hard particulates from thedisrupted waste may be suitable. For example, the segregation step mayrely on differences in size, diameter, hardness, specific gravity,solubility, mobility, frictional coefficient, and any other suitableproperty or combination thereof. A suitable device may distinguish thedisrupted waste from the released hard particulates based on multiplecriteria, either concurrently or serially.

For example, in some embodiments of the present invention, the releasedhard particulates may be segregated from the disrupted waste based upontheir respective sizes. An exemplary suitable device for such asegregation can use a sieve, or any other structure having one or moresize-excluding openings or gaps. Such a structure may have openings thatare sized to retain hard particulates having a minimum mean diameter. Asuitable mean diameter of the retained particulates can be, for example,greater than 1, 2, 4, 8, 12, 16, or 20 centimeters. A preferred meandiameter is about 8 centimeters. The desired gap or opening size is alsoconfigured not to retain the disrupted waste, thereby allowing thedisrupted waste to be passed through the size-excluding structure.

In certain embodiments, the segregation of the waste may be performed ina processive manner, in which the disrupted waste proceeds through thesuitable device, and is subsequently subjected to different segregationcriteria.

It is understood that the present invention also embraces embodiments inwhich steps 104 and 106 are performed concurrently or substantiallyconcurrently. Thus, in such embodiments, the devices used in steps 104and 106 may be integrated, or may even be the same device.

At step 108, the disrupted waste is diluted with a liquid diluent. Incertain embodiments, this step follows the segregation of the disruptedwaste from the released hard particulates. This step can prepare thewaste for further, subsequent processing steps. In addition, bydecreasing the solid content of the waste, the waste may become easierto handle and transport. Decreasing the solid content of the waste alsomay be required for processes such as anaerobic biodigestion of thewaste, as is known in the art (examples of which are described in U.S.Pat. No. 7,014,768, the contents of which are incorporated herein byreference in its entirety).

In some embodiments, the waste can be diluted to a solid content ofabout 5%, about 6%, about 7%, about 8%, about 9%, about 10%, about 11%,12% about 13%, about 15%, about 17%, about 20%, about 25%, about 50%, orany other suitable amount. A preferred solid content is about 12% to13%. The liquid diluent may be any suitable liquid, such as water. Insome embodiments, other liquids, such as complex liquids derived fromother processes may be used, or fed back, to act as a diluent. Use ofsuch complex liquids may act as a source of supplemental components orco-substrates to be mixed with the waste. For example, liquidbiodigestate (or any suitable component thereof) from an anaerobicbiodigester is preferred as the diluent, or the diluent may be composedin part of biodigestate. The addition of biodigestate-derived liquid tothe waste may enhance the subsequent bio-digestion of the waste, and mayalso improve the mixing characteristics of the waste.

FIG. 2 is a flow chart illustrating an exemplary embodiment of a processfor processing waste in accordance with an embodiment of the presentinvention. At step 203, waste, comprising hard particulates embeddedtherein, is loaded. In some embodiments, the loading step is performedby a suitable device or apparatus that conveys waste to the device orapparatus performing step 204, the disruption step. In embodiments inwhich the disruption step has a limited capacity to handle waste, thedevice performing the loading step can regulate the amount of waste soas to supply a suitable amount of waste at a suitable rate. For example,the loading of waste can be provided continuously or in batches.Exemplary devices for loading and providing waste include, withoutlimitation, a hopper, a conveyor belt, and the like.

Steps 204, 206, and 208 generally may be similar to steps 104, 106, and108 from FIG. 1, as described hereinabove.

At step 210, the diluted waste may be heated within the dilution unit.Heat can be provided by heating a vessel in which the diluted waste isbeing held. In some embodiments, heat can be provided by heating atleast some of the diluents used during the dilution step, wherein theliquid diluent has a higher temperature than the waste. In this manner,heating of the waste can occur essentially concurrently with itsdilution (i.e. steps 208 and 210). The liquid can be heated by anexternal heating apparatus or can be heated as part of, or derived from,an exothermic biological or chemical process.

At step 212, metal contaminants may be removed from the diluted waste.It is understood that some or all of the metal contaminants may havealready been removed during the segregation step, as metal contaminantsmay share certain properties with hard particulates that would permittheir selection and segregation from the disrupted waste. In someembodiments, a magnet may be used to extract ferromagnetic metalcontaminants. In some embodiments, the magnet may guide or deflect themetal, so that the metal is retained when the diluted waste is conveyedout or removed from this step, thereby segregating them from the dilutedwaste.

At step 214, the diluted waste is mixed within a dilution unit. Themixing at step 214 can take place for a predetermined amount of time, oruntil a desired consistency or state of the diluted waste is achieved,in some embodiments. In other embodiments, this mixing can be doneconcurrently with the diluting step 208.

It is understood that in some embodiments, any two or more of steps 208,210, 212 and 214 may be performed essentially concurrently. For example,in a single container, the disrupted waste may be diluted and mixed,while heat is introduced and metal contaminants are removed. In someembodiments, any two or more of these steps may be performed inoverlapping phases. In some embodiments, a single integrated device mayperform any two or more of these steps, either sequentially oressentially concurrently. In some embodiments, a single device mayperform two or more of these steps, but where the steps are performedserially or in overlapping steps.

It is also understood that, in some embodiments, steps 208, 210, 212 and214 need not be performed in the order shown, and thus may be performedin any suitable order. For example, in some embodiments, the dilutedwaste may be mixed (step 214) prior to removing the metal contaminants(step 212). In this example, these steps may be performed sequentially,or the subsequent step may overlap with the prior step. In someembodiments, any suitable combination of steps can be performedsimultaneously, which can yield greater efficiency. For example, in someembodiments, step 212 and step 214 can be performed simultaneously,which can yield greater efficiency both with respect to time and deviceutilization.

At step 216, the diluted waste can be conveyed or removed from thedilution unit. This step can be performed by any device that isconfigured or suitable for conveying liquefied or semi-solid material.The device or apparatus may rely on passive conveyance (e.g.gravity-driven flow) or active conveyance (e.g. pumps, conveyer belts,etc.), or any suitable combination thereof. In some embodiments, thedevice or apparatus may be configured so that smaller or otherwise minorparticulates, such as sand or sawdust, can be conveyed without causingsignificant impedance, damage or disruption. Accordingly, segregationstep 106 or 206 may be configured such that minor particulates that willnot result in such impedance, damage or disruption need not besegregated. Such coordination between these, as well as other steps, mayimprove the efficiency and/or the throughput of the overall process.

FIG. 3 illustrates a schematic block diagram illustrating an exemplaryembodiment of a system for processing waste in accordance with thepresent invention. Exemplary system 300 includes waste disrupter 304,segregator 306, and dilution unit 308.

Waste disrupter 304 may be any suitable apparatus or device thatperforms steps 104 or 204, as described herein. Waste disrupter 304receives waste 320, examples of which are described herein. Waste 320can be provided continuously, in batches, or any suitable combinationthereof.

Disrupter 304 is configured to disrupt waste in the manner describedherein, generating disrupted waste 322 from at least a portion of waste320. Disrupted waste 322 can be generated continuously, in batches, orany suitable combination thereof. In addition, disrupted waste 322 canbe generated processively, in which the degree and/or extent ofdisruption waste 320 increases as the waste proceeds through thedisrupter.

Segregator 306 may be any suitable apparatus or device that performssteps 106 or 206, as described herein. At least a portion of disruptedwaste 322 is subjected to segregator 306. Disrupted waste 322 can besubjected to the segregator continuously, in batches, or any suitablecombination thereof. As described herein, segregator 306 may beconfigured as to the criteria and magnitude of separation between thehard particulates and the disrupted waste. Released hard particulates324, following segregation from disrupted waste 322, may be removed fromsegregator 306. This removal may be continuous (e.g. during segregation)or in one or more batches (e.g. following at least a substantial amountof segregation). In some embodiments, released hard particulates 324 maybe retained in segregator 306, while segregated disrupted waste 326 isconveyed or removed. In such embodiments, the retained hard particulatesmay be removed later.

Dilution unit 308 may be any suitable apparatus or device that performssteps 108 or 208, as described herein. Dilution unit 308 can dilutedisrupted waste 326 continuously, in batches, or any suitablecombination thereof. At least a portion of segregated waste 326 issubjected to dilution by dilution unit 308. Diluent 328 may provided todilution unit 308 prior to, following, essentially concurrently with, orany suitable combination thereof to receiving disrupted waste 326.Diluted waste 330 can be generated continuously, in batches, or anysuitable combination thereof.

Referring to system 300, it is understood that in certain embodiments ofthe present invention, suitable combinations or sub-combinations ofdisrupter 304, segregator 306, and dilution unit 308 may be combined orintegrated as a single device.

FIG. 4 illustrates a schematic block diagram of an exemplary system 400for processing waste in accordance with an embodiment of the presentinvention. System 400 can include waste loader 403, wastedisrupter/segregator 405, dilution unit 408 and anaerobic bio-digester418.

Waste loader 403 is a suitable device that can perform loading wastestep 203 described herein. In one embodiment, waste loader 403 can be ahopper, conveyer, or any other suitable device or apparatus that canprovide waste 420. Waste loader can provide waste 420 continuously, inbatches, or any suitable combination thereof.

Waste disrupter/segregator 405 receives the waste from waste loader 403and performs steps 104 and 106, or steps 204 and 206. These two stepsmay be performed essentially concurrently, serially, overlapping, or anysuitable combination thereof. As in system 300, disrupter/segregator 405may also be separated components, in which the disruption andsegregation steps are performed by separate components.

As with segregator 306 of system 300 (in FIG. 3), particulates 424segregated from disrupted waste 426 may be removed fromdisrupter/segregator 405, or may be retained therein for later removal.

Dilution unit 408 may be any suitable apparatus or device that performssteps 108 or 208, as described herein. Dilution unit 408 can dilutesegregated disrupted waste 426 continuously, in batches, or any suitablecombination thereof. At least a portion of segregated waste 426 issubjected to dilution by dilution unit 408. Diluent 436 may be providedto dilution unit 408 prior to, following, essentially concurrently with,or in any suitable combination thereof to disrupted waste 426. Dilutedwaste 430 can be generated continuously, in batches, or in any suitablecombination thereof.

In some embodiments, dilution unit 408 may include a mixing means, suchas described in step 214 herein. In some embodiments, heat 432 may beprovided to dilution unit 408, such as described herein regarding step210 of FIG. 2. Heat may be provided directly to the unit, or may beintroduced via heating of diluent 436.

Some embodiments of system 400 may include anaerobic bio-digester 418.As is known in the art, certain species of micro-organisms, such asmethanogenic bacteria, can grow and metabolize in a substantiallyanaerobic environment. Further, such species produce methane and othergases as by-products. Thus, exemplary anaerobic bio-digesters of thepresent invention are configured to allow anaerobic growth, and may befurther configured to capture or collect methane and othervolatile/gaseous products produced by bacterial metabolism, also knownas biogas.

Thus, diluted waste 430 may be provided to anaerobic bio-digester 418 asa nutrient source for anaerobic bacteria. In some embodiments, such aswhen waste 430 comprises livestock manure, the waste itself may alreadycontain suitable anaerobic bacterial species to allow digestion underanaerobic conditions.

Upon anaerobic digestion of at least a portion of the waste,biodigestate is also produced. Biodigestate includes at least partiallynutrient-depleted media resulting from anaerobic bacterial growth, aswell as the bacteria. Biodigestate may include other volatile andnon-volatile metabolites from bacteria growth. The solid content ofbiodigestate may also vary, depending on the extent of digestion, theinitial moisture/solid content of the waste, and the amount of wateradded to or removed from the bio-digester during the digestion.

As shown in FIG. 4, biodigestate 428 from bio-digester 418, or asubstantially liquid component thereof, may be conveyed to dilution unit408 as diluent 436, and used in the manner described herein. In someembodiments, returned biodigestate 428 may be heated, therebyintroducing heat to diluted waste 430. Using liquid biodigestate can beadvantageous compared to using other liquid diluents, such as water,because compounds in the liquid biodigestate can accelerate the dilutionof the waste, and make diluted waste 430 more suitable and amenable foranaerobic biodigestion.

FIGS. 5A-5B illustrate a side view and a top view, respectively, ofexemplary system 500 for processing waste in accordance with anembodiment of the present invention. Waste processing system 500 caninclude container 502, conveying system 504, open auger 506, disrupterbar 508, rotary screener 510, disrupted waste container 612, conveyingsystem 614, auger 616, container 518, paddles 520, pump 522, andmacerator 524.

System 500 illustrates a preferred exemplary embodiment of the presentinvention, wherein waste disruption, release of hard particulates fromthe disrupted waste, and segregation of released hard particulates fromthe disrupted waste can take place at substantially the same time (e.g.,upon impact with a disrupter bar or other structure).

In FIGS. 5A and 5B, waste can be deposited into system 500 through theopen top of container 502. Conveying system 504 is configured to conveythe waste within container 502 towards the proximal end of open auger506. Conveying system 504 can be any known device that can transportsolid or semi-solid material, such as a walking floor, a conveyer belt,a slatted chain floor, or the like.

Open auger 506, similar to augers known in the art, is configured toconvey waste from its proximal end to its distal end upon appropriaterotation of the auger along its longitudinal axis. As a result, waste isgenerally conveyed out of container 502. Open auger 506 is furtherconfigured to allow waste material that is being conveyed therein toprematurely exit the auger, such as by falling out from the top or sidesof the auger. Open auger 506 can be angled upwards in some embodiments,such that at least some of the waste material that exits open auger 506falls back into container 502. In certain preferred embodiments, openauger 506 can be positioned at an approximate 45 degree angle, whereinthe distal end is elevated with respect to the proximal end. Open auger606 can also be positioned to be angled downwards, or can be positionedto be substantially level. While one open auger is shown in system 500,the present invention is not limited in this regard, such that multipleopen augers, operating substantially in parallel, can be used totransport waste from container 602. In certain preferred embodiments,three open augers can be used in this manner.

While being conveyed by open auger 506, waste can be disrupted bydisrupter bar 508. Disrupter bar 508 is positioned at a pre-determinedproximity with respect to open auger 506 such that the disrupter bar andthe auger acts as a size exclusion device on material being conveyed bythe auger. This proximity is configured-such that material beingconveyed by open auger 506 must be less than a pre-determined sizeparameter (e.g., average diameter) in order to continue conveyance bythe auger. Objects within the material, such as hard particulatesembedded within the waste, that are larger than the pre-determined sizeparameter (e.g., having an average diameter less than about 6, 8, 10, or12 centimeters) will collide with disrupter bar 508 and thus bedislodged from the waste. Smaller particulates can continue to beconveyed by the auger. Likewise, disrupted waste, which can be fracturedor broken upon impacting disrupter bar 508, can also continued to beconveyed.

When such larger hard particulates are dislodged and released bydisrupter bar 508, they can also be segregated from the waste. In someembodiments, the released hard particulates can then fall down thelength or over the sides of open auger 606 back into container 502. Inthis manner, such released hard particulates are segregated from thedisrupted waste.

Disrupter bar 508 can be positioned at any suitable location along thelength of open auger 506. In certain preferred embodiments, disrupterbar 508 can be positioned proximate to the underside of open auger 506.It is preferred to position disrupter bar 508 at a position along theauger such that hard particulates released upon impact with thedisrupter bar fall back into container 502. Disrupter bar 508 can becomposed of any suitable material, and is preferably composed of amaterial having sufficient hardness and durability to withstand repeatedcollisions with hard particulates.

Waste conveyed by open auger 506 can exit the auger's distal end, and bedeposited on rotary screener 510. Rotary screener 510 is configured todisrupt the waste further, thereby releasing additional hardparticulates from the waste. Rotary screener 510 can include a pluralityof rotating cylindrical flights, such as flight 513, which can bemechanically powered. In some embodiments, the flights are configured torotate in the same direction, such as shown by directional arrow 511.Rotary screener 510 contains flights that are substantially at the sameheight as the other flights; however, in some embodiments, the flightscan be at different heights (e.g., rotary screener 510 can be angled),which can assist in directing segregated hard particulates in onedirection. While in the embodiment shown in system 500 utilizescylindrical flights, the present invention is not limited in thisregard, and the flights may be of any shape that can be rotated about alongitudinal axis. Flight 513 includes a plurality of grooves, and aplurality of protuberances, such as protuberance 515, which can enhancedisruption of waste when waste comes into contact with flight 513.

Waste disrupted by rotary screener 510 can fall between the flights intocontainer 512, positioned therebelow. Hard particulates that arereleased from the disrupted waste, due to their size and/or hardness,will not pass between the flights. Instead, such hard particulates aresegregated from the waste by being conveyed across the rotary screenerby the flights, typically in the direction of flight rotation 511. Byadjusting the space between flights, rotary screener 510 can beconfigured to segregate hard particulates of any pre-determined size,with the disrupted waste passing between the flights. Rotary screener510, in some embodiments, is configured to segregate smaller hardparticulates than disrupter bar 508 (e.g., 2 cm in average diameter orless).

In some embodiments, a conveying system (not shown) can be installed toreceive segregated hard particulates are expelled from rotary screener510. This conveying system is configured to remove the segregated hardparticulates from the rotary screener. In some embodiments, a container(not shown) can be placed can be positioned to collect segregated hardparticulates that are expelled from rotary screener 510. This containercan be emptied periodically to prevent excessive buildup or clutteringcaused by the segregated hard particulates.

Waste that passes through rotary screener 510 can fall into container512 positioned therebelow, where it can be conveyed by conveying system514 towards the proximal end of auger 516. Auger 516, in a mannersimilar to that of auger 506, can convey waste from its proximal end toits distal end, thereby removing the conveyed waste from container 512.Auger 516 can be angled upwards in some embodiments, as shown in system500. Auger 516 can also be positioned to be angled downwards orsubstantially level. While a single auger is shown in system 500, thepresent invention is not limited in this regard, such multiple augersoperating substantially in parallel can be used to remove waste fromcontainer 512.

In some embodiments, auger 516 can be optionally substituted with one ormore conveying systems, such as rotary paddles (not shown), that arepositioned to urge material from container 512 to be deposited on arotary screener (not shown), similar to rotary screener 510. In thismanner, the foregoing rotary screener can further disrupt and segregatewaste from container 512. Such segregated waste can then be conveyed toor deposited in container 518.

Waste can be conveyed by auger 516 into container 518. In container 518,waste can be diluted with one or more liquid diluents. Container 518 ispreferably enclosed. Such an enclosure can be advantageous inembodiments where container 518 shares an atmosphere with an anaerobicbio-digester because it can prevent oxygen or other contaminatingmaterial from entering the anaerobic bio-digester. In some embodiments,container 518 can be sealed to prevent or minimize exposure to air.Water can be used as a diluent for the waste in container 518. Water canbe added to the waste using any known method of conveying a liquid (notshown). The water can be pre-heated in some embodiments. A preferreddiluent, which can used in addition to or instead of water, isbiodigestate. Biodigestate can include lignin-containing materials(e.g., straw), as described hereinabove. The biodigestate can be removeddirectly from an anaerobic bio-digester. In certain preferredembodiments, the biodigestate is removed from the anaerobic bio-digesterat the depth where the density corresponds to that of the most digestedmaterial. Removing biodigestate at this depth can be advantageous, as itremoves the more digested waste, thereby enriching the remainingbio-digester contents with the less digested waste for furtherdigestion.

In some embodiments, biodigestate can enter container 518 through pipe526, and can be macerated by macerator 524. Macerator 524 breaks up thebiodigestate, particularly the lignin-containing materials containedtherein, so as to facilitate dilution, pumping of the diluted waste, andto prevent interference with subsequent biodigestion processes.Macerator 524 can be any commercially available macerator. For example,macerator 524 may use counter-rotating blades that can grind thebiodigestate. Macerating the biodigestate can also be advantageousbecause breaking up the lignin-containing materials can promoteanaerobic biodigestion of these lignin-containing materials which, priorto maceration, are substantially undigested. Maceration can therebyincrease overall biogas output.

After, or during, dilution, the waste can be mixed by agitators, such aspaddle 520. Paddle 520 can rotate about its axis and thereby mix thewaste. Diluted waste can be removed from container 518 through pipe 528using pump 522. Diluted waste can be removed from container 518continuously in some embodiments, which can reduce down time. In otherembodiments, diluted waste can be removed from container 518 in batches,which can allow for more thorough dilution of the waste and/or morecomplete mixing.

During the aforementioned dilution and mixing of waste in container 518,grit, sand, and other denser particulates can be allowed to settle outfrom the diluted waste to the bottom of the container. Such settledmaterial can be removed by conveying system 530. In this manner, thediluted waste can be advantageously depleted of such particulates, whichmay interfere with later processes, such as biodigestion.

In some embodiments, an in-line macerator can be configured to maceratethe diluted waste passing through pipe 528. Such embodiments can beadvantageous because the waste may contain lignin-containing materials,which can interfere with pumping and subsequent anaerobic biodigestionprocesses.

While preferred illustrative embodiments of the invention are describedabove, it will be apparent to one skilled in the art that variouschanges and modifications may be made therein without departing from theinvention. The appended claims are intended to cover all such changesand modifications that fall within the true spirit and scope of theinvention.

1. A method of processing organic waste, wherein the waste compriseshard particulates embedded therein, the method comprising: (1)disrupting at least a portion of the organic waste, thereby releasing atleast one of the embedded hard particulates from the waste; (2)segregating at least one of the hard particulates released from thewaste; and then, (3) diluting the waste with a liquid diluent to form amixture suitable for anaerobic digestion to release methane.
 2. Themethod of claim 1, further comprising: (4) providing the wastecontinuously, wherein the disrupting at least a portion of the wastecomprises disrupting at least a portion of the continuously providedwaste.
 3. The method of claim 1, wherein the segregating at least one ofthe released hard particulates comprises segregating at least one of thereleased hard particulates based on a predetermined minimum size of thereleased hard particulates.
 4. The method of claim 3, wherein thepredetermined minimum size is a mean diameter of about 8 centimeters. 5.The method of claim 3, wherein the segregating at least one of thereleased hard particulates based on a predetermined minimum sizecomprises subjecting the released hard particulates and the waste tosize exclusion.
 6. The method of claim 5, wherein the size exclusion isconfigured to exclude hard particulates having the predetermined minimumsize.
 7. The method of claim 6, wherein the predetermined minimum sizeis a mean diameter of about 8 centimeters.
 8. The method of claim 1,wherein the disrupting the waste comprises impacting the waste with atleast one protuberance.
 9. The method of claim 1, wherein the wastefurther comprises metal contaminants, the method further comprisingremoving at least one of the metal contaminants from the waste.
 10. Themethod of claim 9, wherein the removing at least one of the metalcontaminants comprises magnetically removing at least one of the metalcontaminants from the waste.
 11. The method of claim 1, wherein adisrupter bar is positioned proximate an open auger conveying the waste,thereby forming a size exclusion gap therebetween, wherein thedisrupting comprises impacting the conveyed waste with the disrupterbar, thereby releasing at least one of the embedded hard particulates,and wherein the segregation comprises excluding at least one of thereleased hard particulates having a size greater than the size exclusiongap.
 12. The method of claim 1, wherein the disrupting at least aportion of the waste comprises depositing the waste on a rotaryscreener, thereby releasing at least one of the embedded hardparticulates.
 13. The method of claim 1, wherein the diluting the wastestep comprises diluting the waste until the solid content of the wasteis about 12-13%.
 14. The method of claim 1, further comprising heatingthe waste.
 15. The method of claim 1, wherein the liquid diluent has ahigher temperature than the waste.
 16. The method of claim 1, whereinthe diluting the waste further comprises paddle mixing the dilutedwaste.
 17. The method of claim 1, further comprising conveying thediluted waste to an anaerobic bio-digester.
 18. The method of claim 1,wherein the disrupting comprises impacting the waste on a size exclusionapparatus, and wherein the segregating comprises excluding released hardparticulates using the size exclusion apparatus.
 19. The method of claim1, wherein said organic waste comprises livestock manure, animalcarcasses and offal, plant material, wastewater, sewage, food processingwaste, human-derived waste, discarded food, or a mixture thereof. 20.The method of claim 1, wherein said embedded hard particulates compriserocks, metals, or inorganic contaminants that (1) do not undergobiological digestion or decomposition, (2) are resistant to physicalforces, or (3) are insoluble.
 21. The method of claim 1, wherein saidorganic waste, prior to step (3), is in low-moisture/high-solid form.22. The method of claim 1, wherein said organic waste primarilycomprises waste by-products from one or more industries selected fromthe group consisting of agriculture, food processing, animal and plantprocessing, and livestock.
 23. The method of claim 1, wherein saidorganic waste primarily comprises one or more wastes selected from thegroup consisting of livestock manure, animal carcasses and offal, plantmaterial, wastewater, sewage, food processing waste, human-derivedwaste, sewage, wastewater, discarded food, and plant or animal matter.